As environmental concerns become increasingly prevalent in all aspects of industrial and consumer life, the practical and financial demands placed on businesses by strict regulatory standards have skyrocketed. In perhaps no other industry has this been more apparent than in the handling and disposal of regulated materials, such as hazardous wastes and petroleum products. The procedures for containing, transporting, and disposing these materials have become a conglomerate of regulations and standards. Conforming to these standards, while maintaining cost-efficiency and productivity can mean the difference between profitability and failure.
One segment of the industry with a particular set of environmental concerns is the transportation of liquid products. These products may include liquids with high heavy metal concentrations, petroleum products, or other liquids deemed to be dangerous should they be released into the environment or water supply. Tank trucks have proved effective for safely transporting many of these liquids, but problems can arise in transferring the liquids to and from the trucks, such as spills or leaks. Some dry chemicals, such as powdered agricultural chemicals are often transported similarly.
A known solution to this problem is to construct a transfer pad on which the trucks can safely transfer the materials. The transfer pad generally has a slight bowl-like shape, with a gently sloping basin floor leading toward a central sump area. Should any material be spilled during the transfer process, it will be retained in the sump until it can be disposed of properly, such as by being vacuumed out and further transported by truck to a disposal site. Obviously, the pad is formed from a material that is impervious to the liquid being transferred, such as asphalt, concrete or coated concrete.
However, in solving the transfer spill problem, another has arisen with respect to these transfer pads, namely, the accumulation of precipitation. Since a small amount of waste material is retained on the pad or held in the sump, any rainfall or melted snow accumulating on the pad or sump becomes immediately contaminated, and must be disposed of as contaminated waste. At current liquid disposal costs of approximately one dollar per gallon, transporting accumulated rainwater can add up to thousands of dollars per year for a single pad. Worse yet, unexpectedly heavy rainfall might cause the sump to overflow, carrying the regulated products into the neighboring ground areas.
This concern can be met by covering the pad with a roofed building or a canopy. Unfortunately, such buildings can be quite expensive and would require major ventilation systems to expel truck exhaust gases and waste product vapor. Taxes, permits, inspections and fees for such a permanent dwelling also make buildings an unworkable solution. A fixed canopy reduces the cost and vapor handling requirements, but is ineffective in keeping even slightly wind-blown rain off of the transfer pad.
A less expensive known solution is to cover the pad with a standard tarpaulin fastened around the edges of the pad. The tarpaulin must be securely fastened to the ground to prevent it from blowing away in any strong wind, which makes it difficult for a truck operator to make use of the pad. He must first get out of the truck, remove the tarpaulin, usually by untying and then rolling it, and then get back in the truck to drive it onto the pad to begin the fluid transfer. When the transfer is complete, he must drive off the pad, get out of the truck, and cover the pad with the tarpaulin, which usually includes unrolling or unfolding it and tying it down in several places. Tarpaulins also tend to collect water and snow on their top surface, making them difficult to move.